Narcolepsy is a neurological illness that results from the loss or malfunction of certain brain cells that generate hypocretin (orexin), a neurotransmitter that controls alertness and REM sleep. It is not a type of brain injury. Symptoms of this insufficiency include cataplexy, excessive daytime drowsiness, and disturbed sleep at night. It's unclear exactly what causes it, although autoimmune reactions and genetics could be involved. Waklert 150, which contains armodafinil, is frequently used to assist manage symptoms by lowering fatigue and increasing alertness. Although it has an impact on brain function, narcolepsy is not caused by structural brain injury. Medical care is critical.